P0122: Throttle Position Sensor/Switch A Circuit Low Input

Wondering why your check engine light is on? There's a trouble code to clarify. The terrifying thing about that is the mystery of the expense. People often freak out about how much an error message is going to cost them, especially when the messages are combined with terms like “throttle position sensor.” However, it doesn’t help to freak out. If you're asking yourself, “how do I fix trouble code P0122?”, the best thing you can do is research and get answers to the fundamental questions of symptoms, meaning, causes, and solutions.

Decode Your Check Engine Light

Warning Signs

While the idea of an error occurring in a sensor might not seem like a significant issue or concern, this particular sensor, which measures the position of the throttle, can lead to some considerable problems. For example, your vehicle might stall. Or, there might be little to no acceleration. It is also possible that the error message indicates a rough, low, or high idle. Another possible symptom of trouble code P0122 is surging. However, again, depending on the make and model of your vehicle, there might be other symptoms present. Therefore, when you receive this trouble code, you should see about getting the problem resolved as quickly as possible to avoid any further damage.

What Does P0122 Mean?

As a generic powertrain code, this error message refers to many OBD-II compatible vehicles. Primarily, this code relates to the throttle position sensor and its voltage. When notified of this error, it is safe to assume that the A sensor is reporting voltage that is too low, likely between 0.17 and 0.20 volts. With this message appearing, it is safe to assume that the sensor will not operate as it should, which means that you will need to either replace it or repair it. However, the repair procedure is likely different, depending on the make and model of your vehicle.

Potential Causes

While possible resolutions do depend on your specific vehicle, the causes of a P0122 error is typically associated with one of four potential issues. First, the throttle position sensor might not be mounted correctly, causing inaccurate readings and poor connections. Second, the sensor might be experiencing a short in the circuit connecting the unit to the ground wire or another wire. Third, the entire unit might be faulty, resulting in inaccurate voltage readings. Last, the powertrain control module might be damaged, meaning that the throttle position sensor is actually in fine condition.

How to Fix P0122

To fix the error code P0122, you will need first to locate the position of the A circuit. You can find this information in your vehicle’s repair manual. Next, you will want to check the sensor for damage and look at the connections and wiring for any signs of breakage. Then, you will need to check the voltage of the sensor. If too low, you will probably need to replace the part. However, if recently replaced, you might need to adjust the sensor for proper placement. While one of these solutions should work, it is also possible the problem is intermittent, meaning that it is not consistent. If you suspect that is the case, then be extra thorough when checking the wiring, looking for areas where it could be rubbing or grounding.

The OBD-II scanner error code P0122 problem has several possible causes and solutions. Unfortunately, it is possible that you might not be able to resolve the issue on your own. When working with electrical and computer components on your vehicle, diagnosing the problem can be tricky. Although, ignoring the problem is not a solution because it can lead to further damage. Therefore, if you cannot find a resolution, contact an experienced mechanic for help.

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